Refactoring, Clean up and bug fixes

11 files changed, 260 insertions, 158 deletions

diff --git a/src/server/api/endpoints/users/followers.ts b/src/server/api/endpoints/users/followers.ts
index 7fe3ca9943..71081835c7 100644
--- a/src/server/api/endpoints/users/followers.ts
+++ b/src/server/api/endpoints/users/followers.ts
@@ -1,32 +1,49 @@
-import $ from 'cafy'; import ID from '../../../../misc/cafy-id';
+import $ from 'cafy'; import ID, { transform } from '../../../../misc/cafy-id';
 import User, { ILocalUser } from '../../../../models/user';
 import Following from '../../../../models/following';
 import { pack } from '../../../../models/user';
 import { getFriendIds } from '../../common/get-friends';
+import getParams from '../../get-params';
 
-/**
- * Get followers of a user
- */
-export default (params: any, me: ILocalUser) => new Promise(async (res, rej) => {
-	// Get 'userId' parameter
-	const [userId, userIdErr] = $.type(ID).get(params.userId);
-	if (userIdErr) return rej('invalid userId param');
+export const meta = {
+	desc: {
+		'ja-JP': '指定したユーザーのフォロワー一覧を取得します。',
+		'en-US': 'Get followers of a user.'
+	},
+
+	requireCredential: false,
 
-	// Get 'iknow' parameter
-	const [iknow = false, iknowErr] = $.bool.optional.get(params.iknow);
-	if (iknowErr) return rej('invalid iknow param');
+	params: {
+		userId: {
+			validator: $.type(ID),
+			transform: transform,
+		},
 
-	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $.num.optional.range(1, 100).get(params.limit);
-	if (limitErr) return rej('invalid limit param');
+		limit: {
+			validator: $.num.optional.range(1, 100),
+			default: 10
+		},
 
-	// Get 'cursor' parameter
-	const [cursor = null, cursorErr] = $.type(ID).optional.get(params.cursor);
-	if (cursorErr) return rej('invalid cursor param');
+		cursor: {
+			validator: $.type(ID).optional,
+			default: null as any,
+			transform: transform,
+		},
+
+		iknow: {
+			validator: $.bool.optional,
+			default: false,
+		}
+	}
+};
+
+export default (params: any, me: ILocalUser) => new Promise(async (res, rej) => {
+	const [ps, psErr] = getParams(meta, params);
+	if (psErr) return rej(psErr);
 
 	// Lookup user
 	const user = await User.findOne({
-		_id: userId
+		_id: ps.userId
 	}, {
 		fields: {
 			_id: true
@@ -43,7 +60,7 @@ export default (params: any, me: ILocalUser) => new Promise(async (res, rej) =>
 	} as any;
 
 	// ログインしていてかつ iknow フラグがあるとき
-	if (me && iknow) {
+	if (me && ps.iknow) {
 		// Get my friends
 		const myFriends = await getFriendIds(me._id);
 
@@ -53,29 +70,27 @@ export default (params: any, me: ILocalUser) => new Promise(async (res, rej) =>
 	}
 
 	// カーソルが指定されている場合
-	if (cursor) {
+	if (ps.cursor) {
 		query._id = {
-			$lt: cursor
+			$lt: ps.cursor
 		};
 	}
 
 	// Get followers
 	const following = await Following
 		.find(query, {
-			limit: limit + 1,
+			limit: ps.limit + 1,
 			sort: { _id: -1 }
 		});
 
 	// 「次のページ」があるかどうか
-	const inStock = following.length === limit + 1;
+	const inStock = following.length === ps.limit + 1;
 	if (inStock) {
 		following.pop();
 	}
 
-	// Serialize
 	const users = await Promise.all(following.map(f => pack(f.followerId, me, { detail: true })));
 
-	// Response
 	res({
 		users: users,
 		next: inStock ? following[following.length - 1]._id : null,
diff --git a/src/server/api/endpoints/users/following.ts b/src/server/api/endpoints/users/following.ts
index 0e564fd1b6..778ef54a27 100644
--- a/src/server/api/endpoints/users/following.ts
+++ b/src/server/api/endpoints/users/following.ts
@@ -1,32 +1,49 @@
-import $ from 'cafy'; import ID from '../../../../misc/cafy-id';
+import $ from 'cafy'; import ID, { transform } from '../../../../misc/cafy-id';
 import User, { ILocalUser } from '../../../../models/user';
 import Following from '../../../../models/following';
 import { pack } from '../../../../models/user';
 import { getFriendIds } from '../../common/get-friends';
+import getParams from '../../get-params';
 
-/**
- * Get following users of a user
- */
-export default (params: any, me: ILocalUser) => new Promise(async (res, rej) => {
-	// Get 'userId' parameter
-	const [userId, userIdErr] = $.type(ID).get(params.userId);
-	if (userIdErr) return rej('invalid userId param');
+export const meta = {
+	desc: {
+		'ja-JP': '指定したユーザーのフォロー一覧を取得します。',
+		'en-US': 'Get following users of a user.'
+	},
+
+	requireCredential: false,
 
-	// Get 'iknow' parameter
-	const [iknow = false, iknowErr] = $.bool.optional.get(params.iknow);
-	if (iknowErr) return rej('invalid iknow param');
+	params: {
+		userId: {
+			validator: $.type(ID),
+			transform: transform,
+		},
 
-	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $.num.optional.range(1, 100).get(params.limit);
-	if (limitErr) return rej('invalid limit param');
+		limit: {
+			validator: $.num.optional.range(1, 100),
+			default: 10
+		},
 
-	// Get 'cursor' parameter
-	const [cursor = null, cursorErr] = $.type(ID).optional.get(params.cursor);
-	if (cursorErr) return rej('invalid cursor param');
+		cursor: {
+			validator: $.type(ID).optional,
+			default: null as any,
+			transform: transform,
+		},
+
+		iknow: {
+			validator: $.bool.optional,
+			default: false,
+		}
+	}
+};
+
+export default (params: any, me: ILocalUser) => new Promise(async (res, rej) => {
+	const [ps, psErr] = getParams(meta, params);
+	if (psErr) return rej(psErr);
 
 	// Lookup user
 	const user = await User.findOne({
-		_id: userId
+		_id: ps.userId
 	}, {
 		fields: {
 			_id: true
@@ -43,7 +60,7 @@ export default (params: any, me: ILocalUser) => new Promise(async (res, rej) =>
 	} as any;
 
 	// ログインしていてかつ iknow フラグがあるとき
-	if (me && iknow) {
+	if (me && ps.iknow) {
 		// Get my friends
 		const myFriends = await getFriendIds(me._id);
 
@@ -53,29 +70,27 @@ export default (params: any, me: ILocalUser) => new Promise(async (res, rej) =>
 	}
 
 	// カーソルが指定されている場合
-	if (cursor) {
+	if (ps.cursor) {
 		query._id = {
-			$lt: cursor
+			$lt: ps.cursor
 		};
 	}
 
 	// Get followers
 	const following = await Following
 		.find(query, {
-			limit: limit + 1,
+			limit: ps.limit + 1,
 			sort: { _id: -1 }
 		});
 
 	// 「次のページ」があるかどうか
-	const inStock = following.length === limit + 1;
+	const inStock = following.length === ps.limit + 1;
 	if (inStock) {
 		following.pop();
 	}
 
-	// Serialize
 	const users = await Promise.all(following.map(f => pack(f.followeeId, me, { detail: true })));
 
-	// Response
 	res({
 		users: users,
 		next: inStock ? following[following.length - 1]._id : null,
diff --git a/src/server/api/endpoints/users/get_frequently_replied_users.ts b/src/server/api/endpoints/users/get_frequently_replied_users.ts
index 42b6ce20d6..b0fd259588 100644
--- a/src/server/api/endpoints/users/get_frequently_replied_users.ts
+++ b/src/server/api/endpoints/users/get_frequently_replied_users.ts
@@ -1,19 +1,31 @@
-import $ from 'cafy'; import ID from '../../../../misc/cafy-id';
+import $ from 'cafy'; import ID, { transform } from '../../../../misc/cafy-id';
 import Note from '../../../../models/note';
 import User, { pack, ILocalUser } from '../../../../models/user';
+import getParams from '../../get-params';
 
-export default (params: any, me: ILocalUser) => new Promise(async (res, rej) => {
-	// Get 'userId' parameter
-	const [userId, userIdErr] = $.type(ID).get(params.userId);
-	if (userIdErr) return rej('invalid userId param');
+export const meta = {
+	requireCredential: false,
+
+	params: {
+		userId: {
+			validator: $.type(ID),
+			transform: transform,
+		},
 
-	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $.num.optional.range(1, 100).get(params.limit);
-	if (limitErr) return rej('invalid limit param');
+		limit: {
+			validator: $.num.optional.range(1, 100),
+			default: 10
+		},
+	}
+};
+
+export default (params: any, me: ILocalUser) => new Promise(async (res, rej) => {
+	const [ps, psErr] = getParams(meta, params);
+	if (psErr) return rej(psErr);
 
 	// Lookup user
 	const user = await User.findOne({
-		_id: userId
+		_id: ps.userId
 	}, {
 		fields: {
 			_id: true
@@ -83,7 +95,7 @@ export default (params: any, me: ILocalUser) => new Promise(async (res, rej) =>
 	const repliedUsersSorted = Object.keys(repliedUsers).sort((a, b) => repliedUsers[b] - repliedUsers[a]);
 
 	// Extract top replied users
-	const topRepliedUsers = repliedUsersSorted.slice(0, limit);
+	const topRepliedUsers = repliedUsersSorted.slice(0, ps.limit);
 
 	// Make replies object (includes weights)
 	const repliesObj = await Promise.all(topRepliedUsers.map(async (user) => ({
@@ -91,6 +103,5 @@ export default (params: any, me: ILocalUser) => new Promise(async (res, rej) =>
 		weight: repliedUsers[user] / peak
 	})));
 
-	// Response
 	res(repliesObj);
 });
diff --git a/src/server/api/endpoints/users/lists/delete.ts b/src/server/api/endpoints/users/lists/delete.ts
index c56963aab6..1d4513a822 100644
--- a/src/server/api/endpoints/users/lists/delete.ts
+++ b/src/server/api/endpoints/users/lists/delete.ts
@@ -1,5 +1,5 @@
 import $ from 'cafy';
-import ID from '../../../../../misc/cafy-id';
+import ID, { transform } from '../../../../../misc/cafy-id';
 import UserList from '../../../../../models/user-list';
 import { ILocalUser } from '../../../../../models/user';
 import getParams from '../../../get-params';
@@ -15,12 +15,14 @@ export const meta = {
 	kind: 'account-write',
 
 	params: {
-		listId: $.type(ID).note({
+		listId: {
+			validator: $.type(ID),
+			transform: transform,
 			desc: {
 				'ja-JP': '対象となるユーザーリストのID',
 				'en-US': 'ID of target user list'
 			}
-		})
+		}
 	}
 };
 
diff --git a/src/server/api/endpoints/users/lists/push.ts b/src/server/api/endpoints/users/lists/push.ts
index 2d68ec7458..8208e627ed 100644
--- a/src/server/api/endpoints/users/lists/push.ts
+++ b/src/server/api/endpoints/users/lists/push.ts
@@ -1,10 +1,11 @@
-import $ from 'cafy'; import ID from '../../../../../misc/cafy-id';
+import $ from 'cafy'; import ID, { transform } from '../../../../../misc/cafy-id';
 import UserList from '../../../../../models/user-list';
 import User, { pack as packUser, isRemoteUser, getGhost, ILocalUser } from '../../../../../models/user';
 import { publishUserListStream } from '../../../../../stream';
 import ap from '../../../../../remote/activitypub/renderer';
 import renderFollow from '../../../../../remote/activitypub/renderer/follow';
 import { deliver } from '../../../../../queue';
+import getParams from '../../../get-params';
 
 export const meta = {
 	desc: {
@@ -14,20 +15,28 @@ export const meta = {
 
 	requireCredential: true,
 
-	kind: 'account-write'
+	kind: 'account-write',
+
+	params: {
+		listId: {
+			validator: $.type(ID),
+			transform: transform,
+		},
+
+		userId: {
+			validator: $.type(ID),
+			transform: transform,
+		},
+	}
 };
 
-/**
- * Add a user to a user list
- */
 export default async (params: any, me: ILocalUser) => new Promise(async (res, rej) => {
-	// Get 'listId' parameter
-	const [listId, listIdErr] = $.type(ID).get(params.listId);
-	if (listIdErr) return rej('invalid listId param');
+	const [ps, psErr] = getParams(meta, params);
+	if (psErr) return rej(psErr);
 
 	// Fetch the list
 	const userList = await UserList.findOne({
-		_id: listId,
+		_id: ps.listId,
 		userId: me._id,
 	});
 
@@ -35,13 +44,9 @@ export default async (params: any, me: ILocalUser) => new Promise(async (res, re
 		return rej('list not found');
 	}
 
-	// Get 'userId' parameter
-	const [userId, userIdErr] = $.type(ID).get(params.userId);
-	if (userIdErr) return rej('invalid userId param');
-
 	// Fetch the user
 	const user = await User.findOne({
-		_id: userId
+		_id: ps.userId
 	});
 
 	if (user == null) {
diff --git a/src/server/api/endpoints/users/lists/show.ts b/src/server/api/endpoints/users/lists/show.ts
index a2dd00c6e1..585833a2fe 100644
--- a/src/server/api/endpoints/users/lists/show.ts
+++ b/src/server/api/endpoints/users/lists/show.ts
@@ -1,6 +1,7 @@
-import $ from 'cafy'; import ID from '../../../../../misc/cafy-id';
+import $ from 'cafy'; import ID, { transform } from '../../../../../misc/cafy-id';
 import UserList, { pack } from '../../../../../models/user-list';
 import { ILocalUser } from '../../../../../models/user';
+import getParams from '../../../get-params';
 
 export const meta = {
 	desc: {
@@ -10,17 +11,23 @@ export const meta = {
 
 	requireCredential: true,
 
-	kind: 'account-read'
+	kind: 'account-read',
+
+	params: {
+		listId: {
+			validator: $.type(ID),
+			transform: transform,
+		},
+	}
 };
 
 export default async (params: any, me: ILocalUser) => new Promise(async (res, rej) => {
-	// Get 'listId' parameter
-	const [listId, listIdErr] = $.type(ID).get(params.listId);
-	if (listIdErr) return rej('invalid listId param');
+	const [ps, psErr] = getParams(meta, params);
+	if (psErr) return rej(psErr);
 
 	// Fetch the list
 	const userList = await UserList.findOne({
-		_id: listId,
+		_id: ps.listId,
 		userId: me._id,
 	});
 
diff --git a/src/server/api/endpoints/users/lists/update.ts b/src/server/api/endpoints/users/lists/update.ts
index e39f66fb5b..fb1a37b2f1 100644
--- a/src/server/api/endpoints/users/lists/update.ts
+++ b/src/server/api/endpoints/users/lists/update.ts
@@ -1,5 +1,5 @@
 import $ from 'cafy';
-import ID from '../../../../../misc/cafy-id';
+import ID, { transform } from '../../../../../misc/cafy-id';
 import UserList, { pack } from '../../../../../models/user-list';
 import { ILocalUser } from '../../../../../models/user';
 import getParams from '../../../get-params';
@@ -15,18 +15,22 @@ export const meta = {
 	kind: 'account-write',
 
 	params: {
-		listId: $.type(ID).note({
+		listId: {
+			validator: $.type(ID),
+			transform: transform,
 			desc: {
 				'ja-JP': '対象となるユーザーリストのID',
 				'en-US': 'ID of target user list'
 			}
-		}),
-		title: $.str.range(1, 100).note({
+		},
+
+		title: {
+			validator: $.str.range(1, 100),
 			desc: {
 				'ja-JP': 'このユーザーリストの名前',
 				'en-US': 'name of this user list'
 			}
-		})
+		}
 	}
 };
 
diff --git a/src/server/api/endpoints/users/notes.ts b/src/server/api/endpoints/users/notes.ts
index 6934f7c4be..ac6601f64f 100644
--- a/src/server/api/endpoints/users/notes.ts
+++ b/src/server/api/endpoints/users/notes.ts
@@ -1,4 +1,4 @@
-import $ from 'cafy'; import ID from '../../../../misc/cafy-id';
+import $ from 'cafy'; import ID, { transform } from '../../../../misc/cafy-id';
 import getHostLower from '../../common/get-host-lower';
 import Note, { packMany } from '../../../../models/note';
 import User, { ILocalUser } from '../../../../models/user';
@@ -11,100 +11,118 @@ export const meta = {
 	},
 
 	params: {
-		userId: $.type(ID).optional.note({
+		userId: {
+			validator: $.type(ID).optional,
+			transform: transform,
 			desc: {
 				'ja-JP': 'ユーザーID'
 			}
-		}),
+		},
 
-		username: $.str.optional.note({
+		username: {
+			validator: $.str.optional,
 			desc: {
 				'ja-JP': 'ユーザー名'
 			}
-		}),
+		},
 
-		host: $.str.optional.note({
-		}),
+		host: {
+			validator: $.str.optional,
+		},
 
-		includeReplies: $.bool.optional.note({
+		includeReplies: {
+			validator: $.bool.optional,
 			default: true,
 
 			desc: {
 				'ja-JP': 'リプライを含めるか否か'
 			}
-		}),
+		},
 
-		limit: $.num.optional.range(1, 100).note({
+		limit: {
+			validator: $.num.optional.range(1, 100),
 			default: 10,
 			desc: {
 				'ja-JP': '最大数'
 			}
-		}),
+		},
 
-		sinceId: $.type(ID).optional.note({
+		sinceId: {
+			validator: $.type(ID).optional,
+			transform: transform,
 			desc: {
 				'ja-JP': '指定すると、この投稿を基点としてより新しい投稿を取得します'
 			}
-		}),
+		},
 
-		untilId: $.type(ID).optional.note({
+		untilId: {
+			validator: $.type(ID).optional,
+			transform: transform,
 			desc: {
 				'ja-JP': '指定すると、この投稿を基点としてより古い投稿を取得します'
 			}
-		}),
+		},
 
-		sinceDate: $.num.optional.note({
+		sinceDate: {
+			validator: $.num.optional,
 			desc: {
 				'ja-JP': '指定した時間を基点としてより新しい投稿を取得します。数値は、1970年1月1日 00:00:00 UTC から指定した日時までの経過時間をミリ秒単位で表します。'
 			}
-		}),
+		},
 
-		untilDate: $.num.optional.note({
+		untilDate: {
+			validator: $.num.optional,
 			desc: {
 				'ja-JP': '指定した時間を基点としてより古い投稿を取得します。数値は、1970年1月1日 00:00:00 UTC から指定した日時までの経過時間をミリ秒単位で表します。'
 			}
-		}),
+		},
 
-		includeMyRenotes: $.bool.optional.note({
+		includeMyRenotes: {
+			validator: $.bool.optional,
 			default: true,
 			desc: {
 				'ja-JP': '自分の行ったRenoteを含めるかどうか'
 			}
-		}),
+		},
 
-		includeRenotedMyNotes: $.bool.optional.note({
+		includeRenotedMyNotes: {
+			validator: $.bool.optional,
 			default: true,
 			desc: {
 				'ja-JP': 'Renoteされた自分の投稿を含めるかどうか'
 			}
-		}),
+		},
 
-		includeLocalRenotes: $.bool.optional.note({
+		includeLocalRenotes: {
+			validator: $.bool.optional,
 			default: true,
 			desc: {
 				'ja-JP': 'Renoteされたローカルの投稿を含めるかどうか'
 			}
-		}),
+		},
 
-		withFiles: $.bool.optional.note({
+		withFiles: {
+			validator: $.bool.optional,
 			default: false,
 			desc: {
 				'ja-JP': 'true にすると、ファイルが添付された投稿だけ取得します'
 			}
-		}),
+		},
 
-		mediaOnly: $.bool.optional.note({
+		mediaOnly: {
+			validator: $.bool.optional,
 			default: false,
 			desc: {
 				'ja-JP': 'true にすると、ファイルが添付された投稿だけ取得します (このパラメータは廃止予定です。代わりに withFiles を使ってください。)'
 			}
-		}),
+		},
 
-		fileType: $.arr($.str).optional.note({
+		fileType: {
+			validator: $.arr($.str).optional,
 			desc: {
 				'ja-JP': '指定された種類のファイルが添付された投稿のみを取得します'
 			}
-		}),
+		},
 	}
 };
 
@@ -121,7 +139,7 @@ export default (params: any, me: ILocalUser) => new Promise(async (res, rej) =>
 		throw 'only one of sinceId, untilId, sinceDate, untilDate can be specified';
 	}
 
-	const q = ps.userId !== undefined
+	const q = ps.userId != null
 		? { _id: ps.userId }
 		: { usernameLower: ps.username.toLowerCase(), host: getHostLower(ps.host) } ;
 
diff --git a/src/server/api/endpoints/users/relation.ts b/src/server/api/endpoints/users/relation.ts
index 5c7da48349..19643ceed0 100644
--- a/src/server/api/endpoints/users/relation.ts
+++ b/src/server/api/endpoints/users/relation.ts
@@ -1,4 +1,4 @@
-import $ from 'cafy'; import ID from '../../../../misc/cafy-id';
+import $ from 'cafy'; import ID, { transform, ObjectId } from '../../../../misc/cafy-id';
 import { ILocalUser, getRelation } from '../../../../models/user';
 import getParams from '../../get-params';
 
@@ -10,11 +10,13 @@ export const meta = {
 	requireCredential: true,
 
 	params: {
-		userId: $.or($.type(ID), $.arr($.type(ID)).unique()).note({
+		userId: {
+			validator: $.or($.type(ID), $.arr($.type(ID)).unique()),
+			transform: (v: any): ObjectId | ObjectId[] => Array.isArray(v) ? v.map(x => transform(x)) : transform(v),
 			desc: {
 				'ja-JP': 'ユーザーID (配列でも可)'
 			}
-		})
+		}
 	}
 };
 
diff --git a/src/server/api/endpoints/users/search.ts b/src/server/api/endpoints/users/search.ts
index 307a8f6894..a2077b589d 100644
--- a/src/server/api/endpoints/users/search.ts
+++ b/src/server/api/endpoints/users/search.ts
@@ -11,32 +11,36 @@ export const meta = {
 	requireCredential: false,
 
 	params: {
-		query: $.str.note({
+		query: {
+			validator: $.str,
 			desc: {
 				'ja-JP': 'クエリ'
 			}
-		}),
+		},
 
-		offset: $.num.optional.min(0).note({
+		offset: {
+			validator: $.num.optional.min(0),
 			default: 0,
 			desc: {
 				'ja-JP': 'オフセット'
 			}
-		}),
+		},
 
-		limit: $.num.optional.range(1, 100).note({
+		limit: {
+			validator: $.num.optional.range(1, 100),
 			default: 10,
 			desc: {
 				'ja-JP': '取得する数'
 			}
-		}),
+		},
 
-		localOnly: $.bool.optional.note({
+		localOnly: {
+			validator: $.bool.optional,
 			default: false,
 			desc: {
 				'ja-JP': 'ローカルユーザーのみ検索対象にするか否か'
 			}
-		}),
+		},
 	},
 };
 
diff --git a/src/server/api/endpoints/users/show.ts b/src/server/api/endpoints/users/show.ts
index dd09bd5b91..c6f01593d4 100644
--- a/src/server/api/endpoints/users/show.ts
+++ b/src/server/api/endpoints/users/show.ts
@@ -1,35 +1,54 @@
-import $ from 'cafy'; import ID from '../../../../misc/cafy-id';
+import $ from 'cafy'; import ID, { transform, transformMany } from '../../../../misc/cafy-id';
 import User, { pack, ILocalUser, isRemoteUser } from '../../../../models/user';
 import resolveRemoteUser from '../../../../remote/resolve-user';
+import getParams from '../../get-params';
 
 const cursorOption = { fields: { data: false } };
 
-/**
- * Show user(s)
- */
-export default (params: any, me: ILocalUser) => new Promise(async (res, rej) => {
-	let user;
+export const meta = {
+	desc: {
+		'ja-JP': '指定したユーザーの情報を取得します。'
+	},
+
+	requireCredential: false,
 
-	// Get 'userId' parameter
-	const [userId, userIdErr] = $.type(ID).optional.get(params.userId);
-	if (userIdErr) return rej('invalid userId param');
+	params: {
+		userId: {
+			validator: $.type(ID).optional,
+			transform: transform,
+			desc: {
+				'ja-JP': 'ユーザーID'
+			}
+		},
 
-	// Get 'userIds' parameter
-	const [userIds, userIdsErr] = $.arr($.type(ID)).optional.get(params.userIds);
-	if (userIdsErr) return rej('invalid userIds param');
+		userIds: {
+			validator: $.arr($.type(ID)).optional.unique(),
+			transform: transformMany,
+			desc: {
+				'ja-JP': 'ユーザーID (配列)'
+			}
+		},
 
-	// Get 'username' parameter
-	const [username, usernameErr] = $.str.optional.get(params.username);
-	if (usernameErr) return rej('invalid username param');
+		username: {
+			validator: $.str.optional
+		},
 
-	// Get 'host' parameter
-	const [host, hostErr] = $.str.optional.nullable.get(params.host);
-	if (hostErr) return rej('invalid host param');
+		host: {
+			validator: $.str.optional.nullable
+		}
+	}
+};
+
+export default (params: any, me: ILocalUser) => new Promise(async (res, rej) => {
+	const [ps, psErr] = getParams(meta, params);
+	if (psErr) return rej(psErr);
+
+	let user;
 
-	if (userIds) {
+	if (ps.userIds) {
 		const users = await User.find({
 			_id: {
-				$in: userIds
+				$in: ps.userIds
 			}
 		});
 
@@ -38,17 +57,17 @@ export default (params: any, me: ILocalUser) => new Promise(async (res, rej) =>
 		}))));
 	} else {
 		// Lookup user
-		if (typeof host === 'string') {
+		if (typeof ps.host === 'string') {
 			try {
-				user = await resolveRemoteUser(username, host, cursorOption);
+				user = await resolveRemoteUser(ps.username, ps.host, cursorOption);
 			} catch (e) {
 				console.warn(`failed to resolve remote user: ${e}`);
 				return rej('failed to resolve remote user');
 			}
 		} else {
-			const q: any = userId !== undefined
-				? { _id: userId }
-				: { usernameLower: username.toLowerCase(), host: null };
+			const q: any = ps.userId != null
+				? { _id: ps.userId }
+				: { usernameLower: ps.username.toLowerCase(), host: null };
 
 			user = await User.findOne(q, cursorOption);
 
@@ -64,7 +83,7 @@ export default (params: any, me: ILocalUser) => new Promise(async (res, rej) =>
 
 		if (isRemoteUser(user)) {
 			if (user.updatedAt == null || Date.now() - user.updatedAt.getTime() > 1000 * 60 * 60 * 24) {
-				resolveRemoteUser(username, host, { }, true);
+				resolveRemoteUser(ps.username, ps.host, { }, true);
 			}
 		}
 	}